This report echoes a recent New Yorker article on the same topic. From the New York Times today:
Jails across the country have become vast warehouses made up primarily of people too poor to post bail or too ill with mental health or drug problems to adequately care for themselves, according to a report issued Wednesday.
The study, “Incarceration’s Front Door: The Misuse of Jails in America,” found that the majority of those incarcerated in local and county jails are there for minor violations, including driving with suspended licenses, shoplifting or evading subway fares, and have been jailed for longer periods of time over the past 30 years because they are unable to pay court-imposed costs.
While most reform efforts, including early releases and the elimination of some minimum mandatory sentences, have been focused on state and federal prisons, the report found that the disparate rules that apply to jails is also in need of reform.